Welcome to F.A.T. Lab

The Free Art and Technology (F.A.T.) Lab is an organization dedicated to enriching the public domain through the research and development of creative technologies and media. Release early, often and with rap music. This is Notorious R&D.

Yep, it’s a QR code stencil generator! The F.A.T. Lab is pleased to present QR_STENCILER, a free, fully-automated utility which converts QR codes into vector-based stencil patterns suitable for laser-cutting. Additionally, we present QR_HOBO_CODES, a series of one hundred QR stencil designs which, covertly marked in urban spaces, may be used to warn people about danger or clue them into good situations. The QR_STENCILER and the QR_HOBO_CODES join the Adjustable Pie Chart Stencil in our suite of homebrew "infoviz graffiti" tools for locative and situated information display.

ABOUT THIS PROJECTQR codes are a form of two-dimensional barcode which are widely used to convey URLs and other short texts through camera-based smartphones. A variety of free tools exist to generate QR codes (such as the Google Charts API) and to read them (such as TapMedia’s free QR Reader for iPhone app). Our QR_STENCILER is a Java-based software utility which loads a user-specified QR code image — from which it then generates a lasercutter-ready, topologically correct stencil .PDF. As Fred Trotter has pointed out, QR codes contain stencil islands in unpredictable configurations. QR_STENCILER automatically detects and bridges these islands, using thin lines that are minimally disruptive to the highly robust QR algorithm. It does so through the use of two basic image processing techniques: connected component labeling (sometimes called blob detection) and 8-connected chain coding (sometimes called contour tracing). QR_STENCILER was created with Processing, a free, cross-platform programming toolkit for the arts.

Closeup of a QR code lasercut in 1/8"-thick fiberboard. The QR_STENCILER automatically thickens corners between squares (left) and generates "bridges" to connect stencil islands (center). The level (amount) of island bridging is user-adjustable.

Accompanying the QR_STENCILER are the QR_HOBO_CODES (see below), a set of 100 lasercutter-ready QR stencil designs created with the QR_STENCILER software. These stencils can be understood as a covert markup scheme for urban spaces — providing directions, information, and warnings to digital nomads and other indigenterati. We present these as modern equivalents of the chalk-based "hobo signs" developed by 19th century vagabonds and migratory workers to cope with the difficulty of nomadic life. Indeed, our set of QR stencils port a number of classic hobo annotations to the QR format ("turn right here", "dangerous dog", "food for work") as well as some new ones, with a nod to warchalking, that are specific to contemporary conditions ("insecure wifi", "hidden cameras", "vegans beware").

DOWNLOAD & INSTRUCTIONSQR_STENCILER has been tested in MacOSX 10.6.8, but (since Processing is a cross-platform toolkit) it should work in Windows or Linux as well.

Make yourself a QR code image which embeds a short piece of text. GoQR.me, Google and Kaywa all provide free online QR generators. To reduce the complexity of the stencil, we recommend generating your code with the shortest possible texts, and with lower levels of error correction (L-level or M-level). At the same time, we recommend generating QR code images with more pixel resolution, such as 500x500px; for QR_STENCILER, the ideal input image has a “grid size” of about 20 image-pixels per QR grid-cell. (See this QR code for an example; it has 23-pixel grid-cells in an overall image size of 540x540px.)

Although the zip includes compiled executables for Mac, Windows and Linux, we recommend running the QR_STENCILER from the Processing development environment. Download and install the Processing development tool. The QR_STENCILER works with Processing v.1.5.1 or later.

Put your QR code image in the folder, ‘QR_STENCILER/data/’

Launch Processing and open ‘QR_STENCILER.pde’

Press ‘Run’ (Command-R) to start the stenciler.

You will be prompted to Open your QR code image. (A default “hello world” QR code will be opened if none is provided).

After opening the QR code image, the program will generate a stencil .PDF in the ‘data’ folder. Note that there are some options (checkboxes, sliders) which you can use to alter the generated stencils in various ways, including (for example) generating “reverse” (white-on-black) stencils.

The .PDF can be opened in your favorite CAD program, for laser-cutting materials like cardboard, delrin, MDF or acrylic. If you need to find a lasercutter, consider Ponoko.com, which ships anywhere. You can also Google ‘lasercutting service‘ to find a bureau near you, or check the Architecture or Design departments of your local university. (Of course, you could always print out the PDF on paper if you prefer to cut the stencil by hand. Cheap!)

LICENSEThe QR_STENCILER software is provided "as is", without warranty of any kind. QR_STENCILER is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. You are free to distribute, remix, and modify QR_STENCILER, so long as you share alike and provide attribution to FFFFF.AT. The repackaging of QR_STENCILER as or into commercial software, is expressly prohibited. Please note that QR_STENCILER also enjoys protections under the GRL Repercussions 3.0 license. More details about QR_STENCILER’s license and warranty can be found in the preamble to its main code file, QR_STENCILER.pde; for other uses, please contact us. The 100 QR_HOBO_CODES and their respective stencils are hereby dedicated to the public domain.

[...] post is a brief alert to announce the final (updated, v.1.1) release of the F.A.T. Lab’s QR_STENCILER software. This tool is a free, fully-automated utility that converts QR codes into vector-based [...]

[...] QR Hobo Codes, for those hobos carrying a smartphone (via @bruces). before I fall to sleep, here’s a very short video illustrating Minecraft brought to the real world using augmented reality (more specifically, using Kudan’s Qoncept engine). [...]

[...] I’ve been rather fascinated with QR codes as of late. And it seems they’re becoming more and more popular, I’m seeing them in not only in the hip Japanese magazines I have, but the less hip magazines my mother gets too. They’re popping up in TV shows and adverts on the street as well. And people are putting them to other more awesome uses. [...]

> Who are you?
We are a collective of artists, who are concerned with giving people tools to engage with rapidly changing new forms of culture. See our “people” page for information about us as individuals.

> Why did you creat this software?
The Stenciler software was created as a disruptor, in order to allow everyday people a new way to mark up (annotate) their environment. the QR hobo codes were created to demonstrate the software, and spark people’s imaginations about the possibilities.

> Are the software and hobo QR signs widely used in the USA?
Hobo signs used to be very common in the united states, in the early 20th century, but are no longer very common. The QR hobo signs are only two weeks old so I don’t expect they have been widely adopted yet. They are presented as a conjectural or speculative provocation. A small handful of people are already using the stenciler software, such as the folks at GreenGraffiti.com.

> Is this only for fun, or is it really to inform people?
We see no reason why it can’t be both simultaneously. Medicine goes down more easily with a spoonful of sugar.

> Are you still creating new hobo signs?
No, we made 100 and that seemed like enough. Now other people can make their own signs with the tool we provided, as we have demonstrated.

> And what about the true hobo: are they still creating hobo signs?

Handmade chalk signs are still in use by some migrant workers. See the wikipedia article on hobo signs.

It is wrong to assume that a homeless person does not own or need or know how to use a mobile phone, however. Indeed, for some homeless people, their mobile number is the nearest thing they have to a definite address. The nature of “hobo” is changing, thus hobo marks need to change as well. Check out the concept of “technomadism”: homeless people with mobile phones and even laptops. And check out the concept of “warchalking”: marks made to indicate technological features of the environment.

> Do you have any idea whether hobo signs are used in other countries?

For example: (quote from above article):
The first known example of “modern style” graffiti survives in the ancient Greek city of Ephesus (in modern-day Turkey). Local guides say it is an advertisement for prostitution. Located near a mosaic and stone walkway, the graffiti shows a handprint that vaguely resembles a heart, along with a footprint and a number. This is believed to indicate that a brothel was nearby, with the handprint symbolizing payment.

This is fundamentally similar to the use of hobo codes to mark up architecture.

[...] and educate people, do I create a new set of symbols, what information do I want to give? Well these guys have come up with an interesting use for QR Codes which pick up on the idea of Hobo Symbols but use [...]

[...] QR Hobo Codes, for those hobos carrying a smartphone (via @bruces). before I fall to sleep, here’s a very short video illustrating Minecraft brought to the real world using augmented reality (more specifically, using Kudan’s Qoncept engine). [...]

[...] has updated that for the modern world and smart phones. That’s right, someone has made QR Code Hobo Codes. Now, you can just print up templates and spray them with paint out there in the world and people [...]